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Looking for some one to point me towards a good welding forum or a knowledgeable person that no ,s about mig welder problems.

Problem is that i was given a old cig transmig 250 welder (which i have used in the past)it was a great welder!.

i now having problem with it tripping the circuit breaker out when trigger is pulled.

I have isolated the the trigger and lead out of the system ,jumped the wire  to feed motor and it still trips the circuit breaker.

Maybe a good shop to get some parts ,cig site is hopeless unless buying a new shiney one!!.

It is a side project ,as i still have a small lincoln thats good ,so not depending on it.

hope this is right section move if not .

cheers rob

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Is the circuit you are connected to the usual one you use? The circuit could be fully loaded and your unit is tipping it over or the breaker could be fatigued and be in need of replacement. If you have access to a non safety switch protected circuit plug it into that if it trips it is an over current issue. If it doesn't then it is an earth leakage fault. 

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Thanks Dave,um i m Pauline on your question ?

It trips the internal ciruit breaker as soon as you pull the trigger,not welding any think as wouldnt go that long,the fan runs fine .

I suspected the wire drive motor or the hand piece ,but have run the wire feed motor on 12 volts from a seperate source and it runs fine.

I also give it a go with the hand piece completely off the machine (jumped the terminals)and it still tripped the circuit breaker ,after it turns half a turn,

I'm thinking its proberly beyond my knowledge and may take it to someone who no,s .just thought i would try eliminate what i could as it was working fine .

I'm open for any think else i can check 

thanks rob

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As I remember it, the old fusewire melts when too many amps go through it. The new RCD circuit breakers compare the positive an negative currents and when they are different it trips out. They do trip out too often when they're old and need replacing.

If you have RCDs in the house it would be a short going out through the welder somewhere, or the RCD is old and worn out. Swap the RCD for another one & see.

So you've had the motor running without a problem on 12V, and if you run the motor with the cable but no handpiece it drops out??  That suggests a short in the cable somewhere before the handle. The option would be that the motor is crapping out and the RCD can sense that, but a 12V battery doesn't worry and keeps feeding it current.

 

 

 

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Here's my tuppence worth of advice Rob.   

By "internal circuit breaker", do you mean one that is built into the MIG welder itself, or the one in your switchboard ?

A circuit breaker, is basically an isolator switch, but also acts as an automatic fuse if the current (amperes) being drawn, exceed the rating of the switch. 

A RCD is a totally different device, that prevents electrocution, by comparing the current going into the device, on the active wire, to the current coming out, on the neutral wire.

If it differs by more than about 30mA, (30 thousandths of 1 ampere), then it automatically trips.  30mA through the body across the heart area, can kill you.  Basically, if there is less coming back out the neutral, the missing current is leaking to earth. 

That's why some  refer to RCDs as "earth leakage detectors".

If it is the RCD switch that is tripping, do not use it, until it has been "meggered" & tested by an electrician.

Often in workshop equipment, & particularly welders,  on which there are lots of air flow slots, the inside electrics get covered with rubbish, which can often create a leakage path to the frame or ground of the welder.  Have it checked out please.

Cheers Banjo

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Thanks Banjo and Kieth,I'm thinking i will take it to a shop ,before i get fried .

its the circuit breaker ,fuse in the welder that trips ,not the meter box .

Yes I'm thinking that same thing Keith ,as the hand piece checks out ok with ohm meter .and ive checked all the wiring conections.

I'm thinking that the battery direct to motor is giving me false hope that its ok,but is drawing to much current .when hooked up maybe.

i have found a guy local who will look at it ,but as we no with these guys could be a while ,as there busy as .

i will follow up as soon as i no what it is,or if its worth repairing.

thanks every one.

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Hi guys 

Just a follow up on this welder.so it turned out to be a small circuit board that controls the wire feed motor.

The guy that repairs them use to send them away to have them repaired ,but that person has since retired.

So i had to get a new one !!$270 later it works fine.

Its a shame these people retire ,and seemingly don't pass there skills on to the younger ones,seems to happen in a lot of industries these days.

Its turf it buy a new one.

cheers rob

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Hi Rob,      

Quote

Its turf it buy a new one.

Unfortunately, that is the way the world has gone.  

The reason many of us on this forum, are here; is because we like to keep older things going. 

One of the specific problems, with "ewaste" is that electronic components & PCBs in particular, cannot be repaired, even if you haven't retired, or have the ability to do so.

1. Many of the silicon chips become obsolete, so quickly these days, that new replacement, upgraded/enhanced chips are not pin for pin compatible.

2. Most high  volume PCBs are assembled & soldered by automatic machines these days.  The miniaturized parts are very difficult to replace by hand.

On top of that, the mark up on spare parts, is just astronomical.  Several 100% is not uncommon, in most industries.

I've had a habit of "salvaging" any good parts from something that has eventually, "had it day".  It's amazing how many times you get to use them.  Unfortunately, you have to build another shed eventually, to store all the stuff, so the whole exercise, isn't really a cost saving !   The really annoying thing is;  When you finally decide to "turf" something, you've stored for years . . . . . . .  the week after you turfed it, you come across a situation, where you need that particular item, you "turfed".

Such is Life !

Cheers Banjo

 

 

 

 

 

 

 

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